Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F8/00—Chemical modification by after-treatment
  • C08F8/40—Introducing phosphorus atoms or phosphorus-containing groups

Definitions

• This invention relates to modified polystyrene polymers and is more particularly concerned with phospholene-substituted polystyrenes and with processes for their preparation and processes for their use as catalysts for converting isocyanates to carbodiimides.
• This invention comprises polymers characterized by the presence therein of a recurring unit having the formula: ##STR2## wherein the broken lines in the phospholene nucleus indicate a double bond located between the carbon atom at position 3 and one of the carbon atoms at positions 2 and 4, the H atom is attached to whichever carbon atom at positions 2 and 4 is not part of said double bond, R is a substituent selected from the class consisting of halogen, alkoxy from 1 to 6 carbon atoms, inclusive, phenoxy, hydrocarbyl from 1 to 18 carbon atoms, inclusive, and halohydrocarbyl from 1 to 18 carbon atoms, inclusive, m is a whole number from 0 to 3, n is 0 or 1, R 1 is selected from the class consisting of hydrogen and methyl, and R 2 represents hydrocarbyl said hydrocarbyl being free of substituents which are reactive with isocyanate.
• alkoxy from 1 to 6 carbon atoms is inclusive of methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, and isomeric forms thereof.
• hydrocarbyl means the monovalent radical obtained by removing one hydrogen atom from the parent hydrocarbon having the stated number of carbon atoms.
• hydrocarbyl examples include alkyl such as methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, decyl, dodecyl, hexadecyl, octadecyl, and the like, including isomeric forms thereof; alkenyl such as vinyl, allyl, butenyl, pentenyl, octenyl, decenyl, undecenyl, tridecenyl, hexadecenyl, octadecenyl, and the like, including isomeric forms thereof; aralkyl such as benzyl, phenethyl, phenylpropyl, benzhydryl, naphthylmethyl, and the like; aryl such as phenyl, tolyl, xylyl, naphthyl, biphenylyl, and the like; cycloalkyl such
• halohydrocarbyl means hydrocarbyl of the stated carbon atom content having one or more halo substituents.
• the hydrocarbyl group R 2 is free from substituents which are reactive with isocyanate groups. Illustrative of such substituents are halo, i.e. chloro, bromo, fluoro, and iodo; alkoxy as defined supra; alkylmercapto from 1 to 6 carbon atoms, inclusive, such as methylmercapto, ethylmercapto, propylmercapto, butylmercapto, pentylmercapto, hexylmercapto and isomeric forms thereof; and cyano.
• the invention also comprises processes for the preparation of the above polymers and a process for the conversion of organic isocyanates to carbodiimides.
• the polymers of the invention which are characterized by the presence of the recurring group (I), are obtained by chemical modification of at least some of the recurring units of a polystyrene or by first introducing the appropriate phospholene substituent into the benzene ring of a styrene monomer and then polymerizing or copolymerizing the monomer.
• the polymers of the invention can be prepared from the corresponding polystyrene using the following sequence of steps.
• the starting polystyrene is converted to the corresponding nuclear brominated or chloromethylated derivative using the procedures described by Relles et al., JACS, 96, 6469, 1974.
• the bromination of the polystyrene is accomplished by reacting the latter with bromine in the presence of a catlyst such as boron trifluoride.
• the chloromethylation is achieved by reacting the polystyrene with chloromethyl methyl ether in the presence of boron trifluoride.
• the reactants are brought together in the presence of a solvent such as tetrahydrofuran, dimethylformamide, dimethylacetamide, tetramethylenesulfone, cyclohexane, benzene, toluene and the like, and the mixture is maintained under an inert atmosphere such as nitrogen while an excess of metallic lithium, advantageously in the form of newly extruded wire, is added.
• a solvent such as tetrahydrofuran, dimethylformamide, dimethylacetamide, tetramethylenesulfone, cyclohexane, benzene, toluene and the like
• an inert atmosphere such as nitrogen while an excess of metallic lithium, advantageously in the form of newly extruded wire, is added.
• the reaction is generally conducted at ambient temperature (20°-25° C) but higher temperatures, e.g. temperatures up to the reflux temperature of the solvent employed, can be used if desired.
• the above reactions are carried out with the polystyrene or polystyrene derivative in solution or present as an insoluble solid phase.
• the starting material is a polystyrene which has not been crosslinked by copolymerization with, for example, a minor amount of divinylbenzene
• the polystyrene is soluble in polar solvents and the above reactions can be carried out in solution.
• the final product is isolated by, for example, precipitation by the addition of an aliphatic alcohol such as methanol or like solvents in which the product is insoluble.
• the polystyrene is generally reacted, in the form of beads, powdered material, or other forms having relatively small particle size, in suspension with appropriate agitation.
• the phospholene-substituted polystyrenes thus obtained are then subjected to oxidation using hydrogen peroxide or like oxidizing agents to obtain the final polymers having the recurring unit (I).
• the reaction can be carried out conveniently by suspending the phospholene-substituted polystyrene in a polar solvent, such as that set forth above, and adding the oxidizing agent thereto.
• the reaction is advantageously carried out at ambient temperatures but higher temperatures (up to about 70° C) can be employed, if desired.
• polystyrene Any of the commonly available forms of polystyrene can be employed in preparing the polymers of the invention using the above series of reactions.
• the commonly available polystyrenes include the homopolymer of styrene itself, the copolymer of styrene and a minor amount of divinylbenzene (generally 2 percent by weight or less), the homopolymers of vinyltoluene, ⁇ -methylstyrene, and chlorostyrene as well as the copolymers formed from two or more of the aforementioned monomers.
• divinylbenzene generally 2 percent by weight or less
• vinyltoluene ⁇ -methylstyrene
• chlorostyrene chlorostyrene
• the phospholene halides (II) which are employed in the preparation of the polymers of the invention are known compounds which are described, together with processes for their preparation, in U.S. Pat. No. 3,803,225.
• the resulting phospholene-substituted polystyrene is then subjected to oxidation, using the procedure described above, to form the corresponding oxide.
• the above monomers having the formula (III) are prepared by reaction of the appropriate nuclear brominated or chloromethylated styrene monomer and the appropriate phospholene halide (II) using the reaction conditions described above for the corresponding reaction involving the brominated or chloromethylated polystyrene.
• an improved process for the preparation of organic carbodiimides by heating the corresponding organic isocyanate in the presence of a carbodiimide-forming catalyst, the improvement lying in the use as catalyst of a polymer having the recurring unit (I) described above.
• the process can be applied to conversion of any organic isocyanate and it has the advantage over previously employed catalysts that the polymer catalyst always remains in a phase separate from the isocyanate and the resulting carbodiimide and can be readily separated from the latter at the end of the reaction.
• the use of the polymeric catalysts is readily adaptable to continuous type process in which the organic isocyanate to be treated, optionally as a solution in an appropriate organic solvent, is passed through a supported bed or column of catalyst.
• the hold up time in the column is adjusted so that complete conversion, or any desired degree of conversion, can be achieved in a single passage through the column.
• any of the known organic mono or polyisocyanates can be converted to the corresponding carbodiimide using the novel polymeric catalysts of the invention.
• Illustrative of such isocyanates are methyl, ethyl, isopropyl, butyl, hexyl, octyl, octadecyl, allyl, 2-pentyl, cyclopentyl, cyclohexyl, 1-cyclopentenyl, 2-cycloheptenyl, benzyl, phenethyl, 3-phenylpropyl, benzhydryl, 2-naphthylmethyl, naphthyl, phenyl, p-tolyl, o-tolyl, 3-nitrophenyl, 4-methoxyphenyl, 4-allyloxyphenyl, 3,4-xylyl, 2-chlorophenyl, decahydronaphthyl, trifluoromethyl, 2-chloroethy
• the organic isocyanate and the polymeric catalyst are brought together in the proportion of about 0.1 part by weight to about 10 parts by weight of catalyst per 100 parts of isocyanate.
• the reaction is advantageously carried out at elevated temperatures of the order of about 70° to about 200° C.
• the progress of the reaction can be followed readily by measuring the evolution of carbon dioxide which is eliminated in the reaction. Cessation of evolution of the gas generally indicates completion of the reaction.
• the resulting carbodiimide is then readily separated from the catalyst. The separation is facilitated by carrying out the reaction is the presence of an organic solvent in which starting isocyanate and the resulting carbodiimide are soluble.
• the catalyst can be reused repeatedly without losing activity.
• the carbodiimides which are prepared in accordance with this aspect of the process of the invention are known compounds which are useful in preventing ageing and hydrolysis of elastomers; see, for example, U.S. Pat. Nos. 3,297,795 and 3,378,517.

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• Chemical & Material Sciences (AREA)
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• Health & Medical Sciences (AREA)
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• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
• Polyurethanes Or Polyureas (AREA)

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• 1977
  • 1977-01-31 US US05/764,375 patent/US4068055A/en not_active Expired - Lifetime
  • 1977-10-31 US US05/846,973 patent/US4105642A/en not_active Expired - Lifetime
  • 1977-12-21 GB GB53263/77A patent/GB1579200A/en not_active Expired
• 1978
  • 1978-01-12 IT IT47620/78A patent/IT1103257B/it active
  • 1978-01-20 DE DE19782802522 patent/DE2802522A1/de active Granted
  • 1978-01-30 JP JP53009220A patent/JPS6055523B2/ja not_active Expired
  • 1978-01-30 FR FR7802491A patent/FR2378802A1/fr active Granted
  • 1978-01-31 NL NLAANVRAGE7801121,A patent/NL186247C/nl not_active IP Right Cessation

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